Risk of mycoplasma sepsis after cesarean section: a case-control study

Cesarean section (CS), a widely utilized mode of delivery globally, is associated with elevated risks of bloodstream infections (BSIs). Atypical organisms such as Mycoplasma hominis and Ureaplasma urealyticum are often overlooked in clinical practice. Despite their potential to cause severe postpartum sepsis, risk factors and clinical course for mycoplasma BSIs remain poorly defined.

Data were collected from 14,454 women who underwent cesarean delivery at Foshan Maternal and Child Health Hospital. Among them, 27 cases developed sepsis caused by mycoplasma infection. For each case, a control group was established using 1:4 matching on age and admission time. A conditional logistic regression model was employed for statistical analysis.

A total of 135 participants between January 2024 and August 2025 were included. Multivariate analysis identified preoperative leukocytosis as an independent risk factor for postpartum bloodstream infection, with a significant dose-response relationship (OR = 1.93 per 1 × 10⁹/L increase; 95% CI: 1.31-2.82). A clinically relevant WBC cutoff of 10.5 × 10⁹/L was established, above which the infection risk increased more than eightfold (OR = 8.19; 95% CI: 2.31-29.04). subgroup analysis further indicated that preoperative leukocytosis was strongly associated with Ureaplasma urealyticum infection (OR = 33.66; P = 0.011), but not with Mycoplasma hominis. Several procedural factors also showed elevated though non-significant associations with infection risk.

Preoperative leukocytosis was significantly associated with Ureaplasma urealyticum bloodstream infection. This readily available marker could aid in identifying high-risk patients prior to cesarean delivery. The findings support considering targeted prophylaxis in such cases, though further validation is needed.